Existing nursing bottles have problems wherein the contents thereof do not flow out smoothly or leak because of the folding of the nipple if the bottom thereof is not lifted by hand. Accordingly, in order to make the contents flow out smoothly, infants must grasp the nursing bottle by their hand during feeding, which has a problem in that it introduces a significant burden to the infants.
Further, while the nursing bottle is being used, the cap is separated from the nursing bottle and accordingly is easily mislaid or even lost.